28 MANUAL OF TROPICAL AND SUBTROPICAL FRUITS 



.young avocado trees are often injured during the dry summer 

 months by sunburn. 



Another climatic factor which deserves consideration is the 

 danger from high winds. The lower east coast of Florida is 

 occasionally visited by a West Indian hurricane which defoli- 

 ates trees, strips them of their crops, or even breaks them down. 

 Certain parts of California are also subject to occasional high 

 winds, less severe than the hurricane but nevertheless capable 

 of doing much damage. To minimize the danger from this 

 source, it is advisable to keep the trees as low as possible through 

 pruning, since they are then much less liable to injury. The 

 low tree has an additional advantage in that it permits of 

 picking the fruit without the use of tall ladders, and keeps the 

 branches more readily accessible for pruning, spraying, or 

 thinning the fruit. 



In regard to soil the avocado seems to be unusually adapt- 

 able, succeeding on the sandy lands of southern Florida, the 

 volcanic loams of Guatemala and Mexico, the red clays of 

 Cuba and Guatemala, the granite soils of California, and even 

 on heavy adobe, provided the drainage is good. This question 

 is less important, therefore, than many others connected with 

 avocado culture. The chief requisite is good drainage. 



Most of the avocado groves of southeastern Florida are 

 situated upon limestone of the kind shown as Miami oolite. 

 This formation comprises a narrow strip of land extending 

 from above Fort Lauderdale on the north to some miles below 

 Homestead on the south, being widest near the latter place, 

 and nowhere more than thirty feet above sea level. In many 

 parts of this region the rock comes to the surface ; toward the 

 northern end it is commonly overlaid with six inches to two 

 feet of loose light-colored quartz sand, while below Miami the 

 surface soil becomes very scanty, but heavier in nature, contain- 

 ing some clay in certain localities, and being strongly impreg- 

 nated with iron, giving it a reddish color. The rock itself is 



